feat: agent color cfg (#4226)

Co-authored-by: 0xrin <0xrin1@protonmail.com>
Co-authored-by: GitHub Action <action@github.com>

packages/opencode/src/util/color.ts

@@ -0,0 +1,19 @@
+export namespace Color {
+  export function isValidHex(hex?: string): hex is string {
+    if (!hex) return false
+    return /^#[0-9a-fA-F]{6}$/.test(hex)
+  }
+
+  export function hexToRgb(hex: string): { r: number; g: number; b: number } {
+    const r = parseInt(hex.slice(1, 3), 16)
+    const g = parseInt(hex.slice(3, 5), 16)
+    const b = parseInt(hex.slice(5, 7), 16)
+    return { r, g, b }
+  }
+
+  export function hexToAnsiBold(hex?: string): string | undefined {
+    if (!isValidHex(hex)) return undefined
+    const { r, g, b } = hexToRgb(hex)
+    return `\x1b[38;2;${r};${g};${b}m\x1b[1m`
+  }
+}